Compared to the Upper Churchill, which is probably in the range of 2,500 square kilometres, actually in total 5,000 square kilometres of water in a reservoir, Gull Island is 85 square kilometres — 85 square kilometres versus 5,000 square kilometres — and Muskrat Falls is 41 square kilometres because it is all captured in the narrow valley.
Ainsi, seule la gorge sera inondée. Le cours supérieur du fleuve Churchill couvre probablement 2 500 kilomètres carrés environ, et le réservoir contient au total 5 000 kilomètres carrés d'eau.